Education
Mann attended Mount Rainier High School in Des Moines, Washington.
Mann attended Mount Rainier High School in Des Moines, Washington.
He has previously played for the Yokohama BayStars/Yokohama DeNA BayStars of Nippon Professional Baseball (NPB). The Tampa Bay Devil Rays selected Mann in the 27th round of the 2002 MLB draft and signed him to a $47,500 signing bonus, with an additional $40,000 for college expenses. In 2011 and 2012, he pitched for the Yokohama BayStars of Nippon Professional Baseball.
After the 2012 season, Mann signed a minor league contract with an invitation to spring training with the Washington Nationals.
He signed a minor league deal with the Pittsburgh Pirates on December 18, 2013. After starting the 2014 season with the Altoona Curve of the Double-A Eastern League, he was released in May, and played for the Lancaster Barnstormers of the independent Atlantic League of Professional Baseball for the remainder of the 2014 season.
Mann set the American Association single-season strikeout record with 157 strikeouts in 143.2 innings. After the season, his contract was purchased by the Oakland Athletics, and he was assigned to the Triple-A Nashville Sounds.
On February 16, 2016, Mann received an 80-game suspension after testing positive for Ostarine, a performance-enhancing substance.